/**
 * @file main.c
 * @brief  memdev test program
 * 
 * Copyright (C) 2014 JakeYang <add358@gmail.com>
 * 
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */
#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <string.h>

#define DEVICE_NAME "/dev/memdev0"

int main(int argc, char **argv)
{
        int fd = 0;
        char buf[4096]={0};

        /*初始化buf*/
        memcpy(buf,"Mem is char dev!", 16);
        printf("BUF: %s\n",buf);

        fd = open(DEVICE_NAME, O_RDWR);
        if (fd < 0) {
                printf("Open Memdev0 Error!\n");
                return -1;
        }

        write(fd, buf, sizeof(buf)); /*往设备写入数据*/

        lseek(fd,0,SEEK_SET);/*重新定位文件位置（思考没有该指令，会有何后果)*/

        memset(buf, 0, sizeof(buf));
        printf("BUF: %s\n",buf);

        read(fd, buf, sizeof(buf)); /*向设备读数据*/

        printf("BUF: %s\n",buf); /* 这里会输出什么 */

        close(fd);

        return 0;    
}
